The NFL named a new chair to its head, neck and spine committee on Thursday, a Johns Hopkins neurosurgeon who co-authored a paper two years ago titled, "Football and Chronic Traumatic Encephalopathy: How Much Evidence Actually Exists?"
Nicholas Theodore, the director of the Johns Hopkins Neurosurgical Spine Center, will now lead the NFL's committee charged with advising the league on matters related to concussions and other neurological issues.
"He will build on the substantial work of the previous leaders and further advance the health and safety of our sport," Jeff Miller, the league's executive vice president of health and safety, said in a statement.
Theodore's research, according to the NFL, focuses on trauma related to the brain and spinal cord. In May 2016, he co-authored a paper for the World Neurosurgery journal examining some of the evidence associated with football and CTE, the neurogenerative disorder many researchers agree is caused by repetitive brain trauma.
Theodore and his co-author, neurosurgeon Karam Moon, didn't directly answer the question posed in the paper's title, but they did point out what they felt were shortcomings in previous studies linking the sport to CTE.
"As with susceptibility to any neurodegenerative disease, however, that of a repetitively concussed athlete to development of CTE is likely due, in large part, to genetics and environment," they wrote.
The paper was published two months after Miller appeared before the U.S. House Energy and Commerce Committee, where he acknowledged a link between the sport and CTE. The next day the league also issued a statement saying, "The comments made by Jeff Miller yesterday accurately reflect the view of the NFL."
At the time, many researchers hailed the moment on Capitol Hill as a key admission. In the World Neurosurgery paper later that spring, though, Moon and Theodore wrote that further research was still needed, and that there were confounding variables to be considered, "such as opioid use."
"Ultimately, there are likely numerous causes of dementia and cognitive decline in retired athletes, a patient population already at a higher independent risk for substance abuse, depression, and suicide," they wrote.
In an interview Thursday, Theodore said the paper was "a very brief review" that was likely written in 2015 and accepted to the journal the following spring. "It's an evolving topic, obviously, and this was really meant as a very basic, informative article for practicing neurosurgeons, just a few references as a cursory overview on the topic," he said, "nothing more than that."
Asked whether he agreed with the NFL that there is a link between football and CTE, Theodore said, "Between traumatic brain injury and CTE, absolutely. That would encompass football."
Dr. Allen Sills, the NFL's chief medical officer, said he felt the 2016 paper was highlighting the need for further research.
"For those of us in the field, this is not a question of does CTE exist," Sills said. "We all know it exists. We've known that for a very long time. . . .I looked at the piece as a summary of the data but also what are the next steps that need to be done? That's obviously where we still are today in 2018. Lots of people on many fronts are working to answer these questions because they're really important."
In their paper, Theodore and Moon offered critiques of other research related to CTE and football. They cited a 2015 study published in the Neurosurgery journal that studied the "factors in neurodegenerative diseases that may occur in athletes," and they concluded "that much of the evidence has been inconsistent or poorly differentiated from evidence indicative of other neurodegenerative diseases."
And they noted a study done by Boston University neuropathologist Ann McKee that compared concussed athletes with a study group, writing that her research relied on "an inadequate control, given the significant differences in the cohort profile." Miller told the congressional committee he based his assessment that football was linked to CTE partly on the work of McKee, widely regarded as a leader in the field.
Theodore and his colleague pointed to similarities between CTE, Alzheimer's disease and Parkinson's disease, "which raises the question of whether the diagnoses of CTE and AD or PD are mutually exclusive," they wrote.
Because of overlapping clinical and pathologic findings, "the methodology of recent CTE studies does not allow us to accurately characterize CTE as a separate entity yet," they wrote, "especially given the complex nature of the proteins involved." Dr. Bennet Omalu first published a paper 11 years earlier in the journal Neurosurgery called "Chronic Traumatic Encephalopathy in a National Football League Player," though the issue has remained in dispute for many in both the scientific and football worlds.
In the interview Thursday, Theodore said the research today still needs to explore the impact of other confounding factors. "I think between two years ago and now, we definitely have more information, but it's an evolving field," he said. "This is something that's changing literally on a daily basis."
Moon and Theodore worked together at the Barrow Neurological Institute, one of the leading neurological centers in the country. At the time of the paper, Theodore was the chief of the spine section for the Phoenix-based institute's division of neurological surgery. He joined Johns Hopkins in 2016.
While in Phoenix, he served as the team neurosurgeon for the Arizona Cardinals and as consultant to the Arizona Diamondbacks and Arizona Coyotes. He will lead a head, neck and spine committee that is considered one of the NFL's most important for health and safety issues. The group is made up of 12 independent physicians and researchers, plus two consultants, all working on a voluntary basis. The committee was responsible for developing the league's concussion diagnosis and management protocol in 2011. Before Theodore's appointment, neurosurgeons Richard Ellenbogen and Hunt Batjer had co-chaired the committee.
While Theodore and Moon stopped well short of denouncing CTE diagnoses in their 2016 paper, they called for further study of the matter to understand all the confounding factors.
"While we may understand more about [traumatic brain injury] and concussion today than ever before," they wrote, "our understanding of CTE and its relation to sport remains in its infancy, underscoring the role of the neurosurgeon in interpreting the latest evidence and using it to advocate for a safer playing field for all."